holcombe



(N0 Model.) 2 Sheets-Sheet 1.

A. G. HOLGOMBB. APPARATUS POR COVERING ELECTRICv WIRES.

No. 435,629 Padtented Sept. 2, l1890.

' l y I. Snom/16oz @genwfg El@ v -L @a gyw No Model.) 2 Sheets-Sheet 2.

A. G. HOLCOMBE.

APPARATUS ROR UOVRRING ELECTRIC WIRES.

No. 435,629. Patented Sept. 2, 1890.

R Hilti Q Amp UNITED STATES PATENTY OFFICE..

AssIGNoR oF oNE-HALr-fro CHARLES L. BROWNE, 0F NEW.YORK, NJY.

APPARATUS FOR COVERING ELECTRIC WIRES.

srnorrrcn'rron forming part of Lemie-Patent No. 435,629, amd september 2,' 1`s9o. Application filed March 17, 1890. Serial No. 344,145. (No model.)

To all whom it may concern.-

Be it known that I, ALFRED G. HoLcoMBE, a citizen of the United States, residing at Long Island City, in the 'county of Queens and State of New York, have invented certainv new and useful Improvements in Electrical Conductors and in the Method of Manufacturing the same, of which the following is a specification.

The object of my invention is to produce an electrical conductor having a covering of non-carbonizable, indestructible insulating material, and an exterior herinetically-closed tubular sheath of metal.

Of course I am aware that heretofore in a number of instances it lhas been proposed to insulate a wire and then envelop it in a' sheath of metal the edges of which have been sealed or soldered. I do not, therefore, claim as my invention such broad ground; but what I do claim appears from the following speciicat'ion and claims.

In the accompanying drawings, Figure lis a diagrammatic view with part of the apparatus in section, indicating the manner of manufacturing my improved conductor; Fig. 2, a similar view, being a continuation o-f the right-hand end of Fig. l, and Fig. 3 a similar View, being a continuation of the right hand end of Fig. 2; Fig. 4, a detailed View of the forming-wheels, between which the metal ribbon passes as it approaches the insulated conductor; Fig. 5, a similar View of the grooved rolls which fold the ribbon around the insulated conductor as'theyV come together; Fig. 6,a detailed view, being a transverse section of the conductor, showing the wheels for compacting the sheath upon the insulated conductor and by means of which its'welding may be effected; and Fig. 7 is a perspective view illustrating the completed conductor.

The insulating material which'I prefer to use is composed of asbestus and lire-clay, both of which are subjected, either together or separately, to a heat of a temperature sufcient to reduce to ash any combustible or carbonaceous material that maybe contained therein, and when so reduced by heat they are mixed with silicate of soda or other suitable flux. This compound is of a vitreous character and is capable of sustaining the highest temperatures without being destroyed and having its insulated properties impaired. It is the mixture which I prefer to use, but itis specified, not as the only mixture, but as illustrative of a class of compounds, vitreous in character and of high insulating property, that may be employed. This compound I mix with water and form it into a pasty mass of aproper character to be molded around the electrical conductor, and the operation of applying it may be practiced in any of the ordinary ways by which such plasticinsulating compounds are applied around conductors, for instance.

In the drawings, Fig. 1, A is the cylinder of a press, and A the plunger. A hollow core-bar A2 projects into the rear of the'press, and a hollow die A3 projects into its front. The wire passes through them both, and the plastic material is formedarou nd the-conf ductor as itis drawn forward in thesame mannerthat lead pipe andsimilar tubular bod-V ies are made. The hollow die As is preferably prolonged andl enters for any suitable distance into a heatin g and drying box B, through which hot air or products of combustion enter at B and pass olf at B2, thoroughly drying the insulation upon the conductor both as it passes through the prolongation of the die A2 and as it passes uncovered through the heating-box at B3. The insulated conductor leaves the heating-box through a suitable guide B4 and passes betweengrooved rolls C C. (Shown in detail in Fig. 5.) c A The ribbon of metal, which ispreferably a relativelythin ribbon of some ductile metalsuchV as copperortin or alloys of aluminiumis wound upon a reel D andpasses between the rollers D D2, (shown in detail in Fig. 4.,) which rollers have their peripheries shaped to bend the metal into a trough-like formthat is, into U shape-in cross-section. From these rolls the metal ribbon thus shaped passes to the insulated conductor, which lies in the bottom of the trough-shaped ribbon,`

the sides of which are by the wheels C C (shown in detail in Fig. 5) turned over and pressed down upon the insulation with their edges overlapping or'abutting.

As the conductor 'X enters the core-bar A, it passes into contact with a rubber E, from IO O which a wire leads to one pole of a source ofV electrical energy B B. The wire from the tion, the current thatwould` pass by reasonf of the presence of such moisture would tend to dissipate' it. Any vapor resulting from such'an4 operation would have full opportunity to escape, since the metal ribon is not at once closed tightly. Secondly. The galvanometerorcurrent-indicatorserves toindicate when a current sufficient to move the needle passes in the circuit. Thirdly. The alarm device E audibly calls the attention of the attendant in the event of a defect in the insu- Alation of a sufficiently grave character to permit the passage of current enough to sound Y the alarm. Such a defect would be the presence of some foreign conducting body in the insulation, or the scaling off of the insulation.

As the insulating conductor having the ribbon folded thereupon leaves the rolls C C', it passes through a draw-plateF, by which the insulation and the enveloped sheath are j drawn down or reduced in diameter and the vinsulation `more thoroughly compacted. The

power for the draft of the conductor through the draw-plate is furnished by a driven pulley F. After leaving the draw-plate F the conductor passes between two pairs of wheels G G and G G having grooved peripheries.

The peripheries of-these wheels closely envelop` and press upon the metal cover, the wheelsl being mounted in sliding blocks pressed inwardly by coil-springs g. On each side of the wheels a rubber H bears upon the metal sheath, and the rubbers are connected with opposite poles of the source of electrical energy B B. The function of this arrangement may be two-fold-irst, the current passing through the metal sheath is of such quantity as to heat and anneal the sheath which may have been more or less hardened or crystallized by its passage through the draw-plate; second, the quantity of current may be suicient to heat the sheath to such a point as to insure a perfect welding of the seam or joint therein; but in operating according to my invention I may pass the sheathed. conductor through several drawplates, the operation of which alone will weld theedges of the sheath and convert it into a solid tube. After leaving the pulley F the conductor passes through a second draw-plate I, by which the sheath is drawn down and the insulation further compacted. The power for drawing the conductor through this plate is derived from a driven pulley l. After leaving the draw-plate I the sheath is further annealed -by passing in contact with two rubbers K K, connected with opposite poleejtof the source of electrical energy B B2. Nowif it be desired to coat the sheath either with a metalsuchas tin, or zinc, or with asphaltumvarnish or othercompound-it is passed through a bath of the desired material contained in a tank L, from whence it passes around the driven pulley I to a storage-reel (not shown) and is ready for use.

In Fig. 7, X represents the interior conductor, B) the insulating compound, and Cx the enveloping tube or sheath. Among the advantages attending the use of this conductor I may mention the following: It can be heated up to the melting-point of copper Without impairing the insulation. It is not affected by moisture. Hence it can be placed under ground, on the ground,or under water,A and can be attached to trees or poles without insulators. Connecting the metal jacket with the ground is a thorough protection from the effects of lightning. It forms a complete metallic circuit by using the jacket as a return-conductor. The metallic jacket protects the insulation from abrasion. The central conductor is protected from the inductive eifect of currents on other wires. By its use self-induction becomes an advantage instead of a detriment, the philosophy of which is, action produces a current in the jacket in an opposite direction, and as the jacket is a part of the circuit the mutual actionfproduces acceleration instead of retardation. When the current stops, theI induced current being in thev same direction as the primary current, the tailing out or prolongation of the pri'- mary current is prevented. Therefore, for rapid signaling, as in automatic telegraphy, telephoning, or for alternating-current lighting it has great advantages, and the cost will compare favorably with any system where metallic circuits are used. Thus it will be seen that the conductor may be used for any class of electrical work, and as the exterior metal sheath may be used as the return-conductor and may be left uninsulated and in contact or connection with earth, so as to be at the same potential with earth, high-tension currents may be employed without danger.

I claim as my inventionl. The hereindescribed improvement in the art of manufacturing electrical conductors having a central conducting-core, an insulating-compound, and an enveloping metal'- lic sheath, which improvement consists in forming the insulation around the central conductor, drying the same, enveloping the insulated conductor in a metal ribbon applied longitudinally, then passing the conductor thus formed through `a draw-plate, and then annealing the sheath as it leaves the draw-plate, substantially as set forth.

2. The herein-described improvement in the when the current starts the inductive method of manufacturing the conductor herein described, which improvement consists in forming the insulating material around the central core, drying the insulating material, applying the metal ribbon longitudinally around the insulation, passing the conductor thus formed through a draw-plate, and then electrically Welding its edges as it leaves the draw-plate, substantially as set forth.

3. The improvement in the method of manufacturing the conductor herein described, which consists in forming the insulating material around a central core, drying the same, applying they metal ribbon longitudinally around the insulation, passing the conductor thus formed through a draw-plate, electrically annealing the sheath as it leaves the drawplate, then passing it through another drawplate and electricallyannealing it as it leaves the second draw-plate, substantially as set forth. j

4. The combination, substantially as set forth, of a mechanism for forming the insulation around the central core or conductor, the metal-ribbon roll, the rolls D D2, the for.- mer having a convex and the latter a concave periphery to give the ribbon a trough-like form,and the rolls C C', both having concave peripheries for folding the trough-shaped ribbon around the insulation.

5. The combination, substantially as set forth, ofmeans for forming the insulation around the central conductor, the metal ribbon, means for applying it around the msullation, and the electric circuit containing a galvanometer and including the ribbon, the insulation, and the central conductor.

`6. The combination, substantially as set forth, of means for forming the insulation around the central conductor, the metal ribbon, means for applying it around the insulation, and the electric circuit containing-an alarm device and including the ribbon, the insulation, and the central conductor.

7. The herein-described method of making an insulated conductor,which consists in subjecting non-carbonizable insulating material exposed to the air to a high temperature to A eliminate or reduce to ash any carbonizablc foreign matter that may be contained therein, then mixing the insulating material in to a plastic mass by admixture with a suitable liquid, molding such plastic material around the. Wire, drying it as the wire is drawn forward, and applying a metal sheath as the insulated wire leaves the drier. V

In testimony whereof I have hereunto sub- :scribed my, name.

ALFRED G. HOLCOMBE. Witnesses:

EDWARD C. DAVIDSON, MAMIE J. KELLEY. 

